CN111036154A - Preparation method of sodium alginate-chitosan composite microcapsules based on aqueous two-phase system - Google Patents

Abstract

Translated fromChinese

本发明提供了一种基于双水相体系的海藻酸钠‑壳聚糖复合微囊制备方法。该方法包括微流控芯片的制备、双水相溶液的准备、微流体的操控、海藻酸钠‑壳聚糖复合微囊的形成和表征等。本发明以集成了气动泵阀的微流控芯片为技术平台，以双水相体系为成型模板，通过一步法将分子表面具有相反电荷的海藻酸钠和壳聚糖精准可控地制备为复合微囊。该微囊可用于生物活性物质的负载与运输，如蛋白类药物、益生菌和细胞等，在疾病治疗、生物工程和再生医学等领域发挥巨大作用。The invention provides a preparation method of sodium alginate-chitosan composite microcapsules based on a two-phase system. The method includes the preparation of a microfluidic chip, the preparation of a two-phase solution, the manipulation of microfluidics, the formation and characterization of sodium alginate-chitosan composite microcapsules, and the like. The invention uses a microfluidic chip integrated with a pneumatic pump valve as a technical platform, and a two-phase system as a molding template to accurately and controllably prepare a composite of sodium alginate and chitosan with opposite charges on the molecular surface through a one-step method. Microcapsules. The microcapsules can be used to load and transport biologically active substances, such as protein drugs, probiotics and cells, and play a huge role in disease treatment, bioengineering, and regenerative medicine.

Description

Preparation method of sodium alginate-chitosan composite microcapsule based on aqueous two-phase system

Technical Field

The invention belongs to the fields of micro-fluidic technology, material chemistry and the like, and particularly relates to a preparation method of a sodium alginate-chitosan composite microcapsule based on a two-aqueous-phase system.

Background

Sodium alginate and chitosan are used as two natural hydrogel substances, and are widely applied to the fields of biology, medicine, pharmacy, food and the like due to high water-bearing property, good biocompatibility and mild gelling conditions. The molecular surfaces of the two substances have a large amount of residual charges (sodium alginate is negatively charged, and chitosan is positively charged), so that the two substances can also be regarded as two natural polyelectrolytes, and the two substances can also directly react in an aqueous solution to obtain the composite polymer. The polymer can be in the forms of films, microspheres, microcapsules and the like, and is widely applied to the fields of food engineering, drug carriers, tissue engineering and the like due to good biocompatibility and mechanical strength.

In various shapes formed by the sodium alginate-chitosan composite material, the microcapsule is considered as a good micro carrier, can be used for loading and delivering medicines, bacteria, cells and the like, and has wide application prospects in the fields of biology, medicine, pharmacy and the like. However, the traditional microcapsule forming method usually involves multi-step operation, firstly preparing solid sodium alginate microspheres, then assembling chitosan and sodium alginate on the surface layer of the microspheres, and finally dissolving the sodium alginate inside to obtain the hollow microcapsules. The preparation process is complex and time-consuming, has large damage to the loaded object and low loading efficiency, and is not beneficial to the wide application of the microcapsule.

In recent years, the microfluidic droplet technology has been developed greatly, and various functionalized microspheres and microcapsules with different morphologies can be accurately prepared, which makes great contribution in the fields of materials science, biology, pharmacy and the like. The introduction of the aqueous two-phase system into the field of microfluidic droplets makes it possible to prepare microspheres and microcapsules with more complex shapes. And the possibility of industrialization of the prepared products is greatly increased due to the advantages of accurate controllability, high flux and the like of the microfluidic technology. The invention utilizes a micro-fluidic chip integrated with a pneumatic pump valve and a double water phase system to prepare the sodium alginate-chitosan composite microcapsule with controllable appearance and higher yield in the chip by a one-step method.

Disclosure of Invention

The invention aims to provide a preparation method of a sodium alginate-chitosan composite microcapsule based on an aqueous two-phase system, and aims to provide early technical support for the development of pharmacy, regenerative medicine, food engineering and the like.

The technical solution of the invention is as follows: a preparation method of a sodium alginate-chitosan composite microcapsule based on an aqueous two-phase system comprises the following steps:

(1) preparing a micro-fluidic chip: preparing a Polydimethylsiloxane (PDMS) chip integrated with a pneumatic pump valve by using a conventional soft lithography method; the chip is used for generating a liquid drop template and preparing a sodium alginate-chitosan composite microcapsule,

the chip comprises a continuous phase inlet containing chitosan, a continuous phase inlet, a gas inlet, a dispersed phase inlet containing sodium alginate, a microcapsule outlet, a continuous phase channel containing chitosan, a continuous phase channel, a gas channel, a dispersed phase channel containing sodium alginate, a droplet template forming channel, a microcapsule forming channel, a pneumatic micro valve, an intersection 1 and anintersection 2;

the continuous phase inlet containing chitosan is connected with the microcapsule outlet through the continuous phase channel containing chitosan, theintersection 2 and the microcapsule forming channel; the continuous phase inlet and the dispersed phase inlet containing sodium alginate are respectively connected with the intersection 1 through a continuous phase channel and a dispersed phase channel containing sodium alginate, and then are connected with the microcapsule outlet through achannel intersection 2 formed by a droplet template and a microcapsule forming channel; the gas inlet is connected with the pneumatic micro valve through a gas channel;

(2) preparation of aqueous two-phase solution: dissolving sodium alginate in aqueous solution of dextran as dispersed phase containing sodium alginate, using aqueous solution of polyethylene glycol (PEG) as continuous phase, and dissolving chitosan in aqueous solution of PEG as continuous phase containing chitosan. The dispersed phase containing sodium alginate can be mixed with water-soluble drugs, probiotics or cells to realize the loading of corresponding substances;

(3) manipulation of microfluidics: the continuous phase containing chitosan enters the micro-fluidic chip through the inlet and then reaches theintersection 2 along the continuous phase channel containing chitosan; the continuous phase, the compressed air and the dispersed phase containing sodium alginate sequentially pass through the continuous phase inlet, the gas inlet and the dispersed phase inlet containing sodium alginate into the microfluidic chip, and then sequentially pass through the continuous phase channel, the gas channel and the dispersed phase channel containing sodium alginate to reach the intersection 1, wherein the compressed air drives the pneumatic pump valve to periodically expand, so that the dispersed phase channel containing sodium alginate is extruded, and the formation of dispersed phase droplets containing sodium alginate is promoted;

(4) and (3) forming and characterizing the sodium alginate-chitosan composite microcapsule: and (3) forming a channel by the dispersed phase droplet containing the sodium alginate in the step (3) to reach theintersection 2, and contacting the continuous phase droplet with chitosan at the intersection, wherein sodium alginate molecules with negative charges on the surface of the droplet and chitosan with positive charges outside the droplet are subjected to cross-linking reaction on the surface of the droplet to form the sodium alginate-chitosan composite microcapsule taking the dispersed phase droplet containing the sodium alginate as the template. The composite microcapsule can be characterized by means of an optical microscope, an electron microscope and the like so as to observe the appearance, the size and the like of the composite microcapsule.

The distance between the pump valve and the disperse phase channel is 40-60 μm, the width of the disperse phase channel between the pump valves is 40-60 μm, and the width and height of all the channels are 100-400 μm.

The PEG molecular weight range used: 4000-20000Da, concentration range: 5-50% (g/ml); dextran molecular weight range: 70k-500kDa, concentration range: 5-20% (g/ml); sodium alginate viscosity range: 55-850cps, concentration range: 0.5-2% (g/ml); viscosity range of chitosan: 100-400cps, concentration range: 0.5-3% (g/ml).

Applied chitosan-containing continuous phase flow rate range: 2-6 ul/min; continuous phase flow rate range: 1-4 ul/min; gas pressure range: 10-60 kPa; flow rate range of the dispersed phase containing sodium alginate: 0.1-0.4 ul/min; the operation cycle range of the pneumatic pump valve is as follows: 0.1-0.8 s.

The invention takes a micro-fluidic chip integrated with a pneumatic pump valve as a technical platform, takes a two-aqueous phase system as a forming template, and prepares sodium alginate and chitosan with opposite charges on the molecular surface into a composite microcapsule in a precise and controllable way by a one-step method. The microcapsule can be used for loading and transporting bioactive substances, such as protein medicines, probiotics, cells and the like, and plays a great role in the fields of disease treatment, bioengineering, regenerative medicine and the like.

Drawings

Fig. 1 is a schematic diagram of the structure of the microfluidic chip.

FIG. 2 is an optical microscopic representation (scale: 200 μm) of the composite microcapsules of example 1.

Fig. 3 is a representation of the composite microcapsules of example 2, wherein: a optical microscope characterization (scale: 100 μm); b Scanning Electron Microscopy (SEM) characterization (scale: 100 μm).

FIG. 4 is a representation of the composite microcapsule-loaded islet cells of example 3, wherein: a, optical microscope characterization picture; b fluorescence microscopy characterization (scale: 50 μm).

Detailed Description

Several fluids of a double-aqueous phase system are sequentially introduced into a micro-fluidic chip prepared by a micro-processing technology, and the controllable one-step preparation of the sodium alginate-chitosan composite microcapsule is realized by controlling a pneumatic pump valve. The prepared microcapsule can be characterized by using an optical microscope, an electron microscope and the like. The invention is further illustrated by the following figures and examples.

Example 1

A preparation method of sodium alginate-chitosan composite microcapsules based on an aqueous two-phase system comprises the following steps:

(1) preparing a micro-fluidic chip: preparing a Polydimethylsiloxane (PDMS) chip integrated with a pneumatic pump valve by using a conventional soft lithography method; the chip is used for generating a liquid drop template and preparing a sodium alginate-chitosan composite microcapsule,

the chip comprises a continuous phase inlet 1 containing chitosan, acontinuous phase inlet 2, agas inlet 3, a dispersedphase inlet 4 containing sodium alginate, amicrocapsule outlet 5, acontinuous phase channel 6 containing chitosan, acontinuous phase channel 7, agas channel 8, a dispersedphase channel 9 containing sodium alginate, a droplettemplate forming channel 10, amicrocapsule forming channel 11, a pneumaticmicro valve 12, an intersection 1(13) and an intersection 2 (14);

the chitosan-containing continuous phase inlet 1 is connected with themicrocapsule outlet 5 through the chitosan-containingcontinuous phase channel 6, the intersection 2(14) and themicrocapsule forming channel 11; thecontinuous phase inlet 2 and the dispersedphase inlet 4 containing sodium alginate are respectively connected with the intersection 1(13) through thecontinuous phase channel 7 and the dispersedphase channel 9 containing sodium alginate, and then connected with themicrocapsule outlet 5 through the droplettemplate forming channel 10, the intersection 2(14) and themicrocapsule forming channel 11; thegas inlet 3 is connected with a pneumaticmicro valve 12 through agas channel 8; as shown in fig. 1. Wherein, the distance between the pump valve and the disperse phase channel is 40 μm, the width of the disperse phase channel between the pump valves is 40 μm, and the width and the height of all the channels are 150 μm.

The chitosan-containing continuous phase inlet 1 is connected with themicrocapsule outlet 5 through the chitosan-containingcontinuous phase channel 6, the intersection 2(14) and themicrocapsule forming channel 11; thecontinuous phase inlet 2 and the dispersedphase inlet 4 containing sodium alginate are respectively connected with the intersection 1(13) through thecontinuous phase channel 7 and the dispersedphase channel 9 containing sodium alginate, and then connected with themicrocapsule outlet 5 through the droplettemplate forming channel 10, the intersection 2(14) and themicrocapsule forming channel 11; thegas inlet 3 is connected with a pneumaticmicro valve 12 through agas channel 8;

(2) preparation of aqueous two-phase solution: dissolving sodium alginate in aqueous solution of dextran as dispersed phase containing sodium alginate, using aqueous solution of polyethylene glycol (PEG) as continuous phase, and dissolving chitosan in aqueous solution of PEG as continuous phase containing chitosan. The PEG molecular weight used: 6000Da, concentration: 10% (g/ml); dextran molecular weight: 70kDa, concentration: 5% (g/ml); viscosity of sodium alginate: 55cps, concentration: 0.5% (g/ml); viscosity of chitosan: 100cps, concentration: 0.5% (g/ml).

(3) Manipulation of microfluidics: the continuous phase containing chitosan enters the microfluidic chip through the inlet 1 and then reaches the intersection 2(14) along thecontinuous phase channel 6 containing chitosan; the continuous phase, the compressed air and the dispersed phase containing sodium alginate sequentially enter the micro-fluidic chip through thecontinuous phase inlet 2, thegas inlet 3 and the dispersedphase inlet 4 containing sodium alginate, and then sequentially reach the intersection 1(13) along thecontinuous phase channel 7, thegas channel 8 and the dispersedphase channel 9 containing sodium alginate, wherein the compressed air drives the pneumatic pump valve to periodically expand, so that the dispersedphase channel 9 containing sodium alginate is extruded, and the formation of dispersed phase droplets containing sodium alginate is promoted. Wherein, the continuous phase flow rate containing chitosan is as follows: 2 ul/min; continuous phase flow rate: 2 ul/min; gas pressure: 10 kPa; flow rate of dispersed phase containing sodium alginate: 0.1 ul/min; the operation period of the pneumatic pump valve is as follows: 0.2 s.

(4) And (3) forming and characterizing the sodium alginate-chitosan composite microcapsule: and (3) the dispersed phase droplet containing the sodium alginate formed in the step (3) reaches the intersection 2(14) through the droplettemplate forming channel 10, and is contacted with the continuous phase containing chitosan, and the sodium alginate molecules with negative charges on the surface of the droplet and the chitosan with positive charges outside the droplet are subjected to cross-linking reaction on the surface of the droplet to form the sodium alginate-chitosan composite microcapsule taking the dispersed phase droplet containing the sodium alginate as the template. The composite microcapsule can be characterized by optical microscope to observe its morphology and size, etc., as shown in fig. 2.

Example 2

A preparation method of sodium alginate-chitosan composite microcapsules based on an aqueous two-phase system comprises the following steps:

(1) preparing a micro-fluidic chip: preparing a Polydimethylsiloxane (PDMS) chip integrated with a pneumatic pump valve by using a conventional soft lithography method; the chip is used for generating a liquid drop template and preparing a sodium alginate-chitosan composite microcapsule,

the chip comprises a continuous phase inlet 1 containing chitosan, acontinuous phase inlet 2, agas inlet 3, a dispersedphase inlet 4 containing sodium alginate, amicrocapsule outlet 5, acontinuous phase channel 6 containing chitosan, acontinuous phase channel 7, agas channel 8, a dispersedphase channel 9 containing sodium alginate, a droplettemplate forming channel 10, amicrocapsule forming channel 11, a pneumaticmicro valve 12, an intersection 1(13) and an intersection 2 (14);

the chitosan-containing continuous phase inlet 1 is connected with themicrocapsule outlet 5 through the chitosan-containingcontinuous phase channel 6, the intersection 214 and themicrocapsule forming channel 11; thecontinuous phase inlet 2 and the dispersedphase inlet 4 containing sodium alginate are respectively connected with the intersection 1(13) through thecontinuous phase channel 7 and the dispersedphase channel 9 containing sodium alginate, and then connected with themicrocapsule outlet 5 through the droplettemplate forming channel 10, the intersection 2(14) and themicrocapsule forming channel 11; thegas inlet 3 is connected with a pneumaticmicro valve 12 through agas channel 8; as shown in fig. 1. Wherein, the distance between the pump valve and the disperse phase channel is 60 μm, the width of the disperse phase channel between the pump valves is 60 μm, and the width and the height of all the channels are 400 μm.

(2) Preparation of aqueous two-phase solution: dissolving sodium alginate in aqueous solution of dextran as dispersed phase containing sodium alginate, using aqueous solution of polyethylene glycol (PEG) as continuous phase, and dissolving chitosan in aqueous solution of PEG as continuous phase containing chitosan. The PEG molecular weight used: 20000Da, concentration: 40% (g/ml); dextran molecular weight: 500kDa, concentration: 20% (g/ml); viscosity of sodium alginate: 850cps, concentration: 2% (g/ml); viscosity of chitosan: 400cps, concentration: 3% (g/ml).

(3) Manipulation of microfluidics: the continuous phase containing chitosan enters the microfluidic chip through the inlet 1 and then reaches the intersection 2(14) along thecontinuous phase channel 6 containing chitosan; the continuous phase, the compressed air and the dispersed phase containing sodium alginate sequentially enter the micro-fluidic chip through thecontinuous phase inlet 2, thegas inlet 3 and the dispersedphase inlet 4 containing sodium alginate, and then sequentially reach the intersection 1(13) along thecontinuous phase channel 7, thegas channel 8 and the dispersedphase channel 9 containing sodium alginate, wherein the compressed air drives the pneumatic pump valve to periodically expand, so that the dispersedphase channel 9 containing sodium alginate is extruded, and the formation of dispersed phase droplets containing sodium alginate is promoted. Wherein, the continuous phase flow rate containing chitosan is as follows: 6 ul/min; continuous phase flow rate: 4 ul/min; gas pressure: 60 kPa; flow rate of dispersed phase containing sodium alginate: 0.4 ul/min; the operation period of the pneumatic pump valve is as follows: 0.8 s.

(4) And (3) forming and characterizing the sodium alginate-chitosan composite microcapsule: and (3) the dispersed phase droplet containing the sodium alginate formed in the step (3) reaches the intersection 2(14) through the droplettemplate forming channel 10, and is contacted with the continuous phase containing chitosan, and the sodium alginate molecules with negative charges on the surface of the droplet and the chitosan with positive charges outside the droplet are subjected to cross-linking reaction on the surface of the droplet to form the sodium alginate-chitosan composite microcapsule taking the dispersed phase droplet containing the sodium alginate as the template. The composite microcapsule can be characterized by optical microscope and electron microscope to observe its morphology and size, etc., as shown in fig. 3.

Example 3

A preparation method of sodium alginate-chitosan composite microcapsules based on an aqueous two-phase system comprises the following steps:

(1) preparing a micro-fluidic chip: preparing a Polydimethylsiloxane (PDMS) chip integrated with a pneumatic pump valve by using a conventional soft lithography method; the chip is used for generating a liquid drop template and preparing a sodium alginate-chitosan composite microcapsule,

the chip comprises a continuous phase inlet 1 containing chitosan, acontinuous phase inlet 2, agas inlet 3, a dispersedphase inlet 4 containing sodium alginate, amicrocapsule outlet 5, acontinuous phase channel 6 containing chitosan, acontinuous phase channel 7, agas channel 8, a dispersedphase channel 9 containing sodium alginate, a droplettemplate forming channel 10, amicrocapsule forming channel 11, a pneumaticmicro valve 12, an intersection 1(13) and an intersection 2 (14);

the chitosan-containing continuous phase inlet 1 is connected with themicrocapsule outlet 5 through the chitosan-containingcontinuous phase channel 6, the intersection 2(14) and themicrocapsule forming channel 11; thecontinuous phase inlet 2 and the dispersedphase inlet 4 containing sodium alginate are respectively connected with the intersection 1(13) through thecontinuous phase channel 7 and the dispersedphase channel 9 containing sodium alginate, and then connected with themicrocapsule outlet 5 through the droplettemplate forming channel 10, the intersection 2(14) and themicrocapsule forming channel 11; thegas inlet 3 is connected with a pneumaticmicro valve 12 through agas channel 8; as shown in fig. 1. Wherein, the distance between the pump valve and the disperse phase channel is 60 μm, the width of the disperse phase channel between the pump valves is 50 μm, and the width and the height of all the channels are 350 μm.

(2) Preparation of aqueous two-phase solution: dissolving sodium alginate in aqueous solution of dextran as dispersed phase containing sodium alginate, using aqueous solution of polyethylene glycol (PEG) as continuous phase, and dissolving chitosan in aqueous solution of PEG as continuous phase containing chitosan. Mixing the dispersed phase containing sodium alginate at a concentration of about 10⁷The load was carried out on islet cells (β -TC 6). The PEG used had a molecular weight of 20000Da and a concentration of 17% (g/ml), the dextran had a molecular weight of 500kDa and a concentration of 15% (g/ml), the sodium alginate had a viscosity of 55cps and a concentration of 1% (g/ml), and the chitosan had a viscosity of 200cps and a concentration of 1% (g/ml).

(3) Manipulation of microfluidics: the continuous phase containing chitosan enters the microfluidic chip through the inlet 1 and then reaches the intersection 2(14) along thecontinuous phase channel 6 containing chitosan; the continuous phase, the compressed air and the dispersed phase containing sodium alginate sequentially enter the micro-fluidic chip through thecontinuous phase inlet 2, thegas inlet 3 and the dispersedphase inlet 4 containing sodium alginate, and then sequentially reach the intersection 1(13) along thecontinuous phase channel 7, thegas channel 8 and the dispersedphase channel 9 containing sodium alginate, wherein the compressed air drives the pneumatic pump valve to periodically expand, so that the dispersedphase channel 9 containing sodium alginate is extruded, and the formation of dispersed phase droplets containing sodium alginate is promoted. Wherein, the continuous phase flow rate containing chitosan is as follows: 4 ul/min; continuous phase flow rate: 2 ul/min; gas pressure: 20 kPa; flow rate of dispersed phase containing sodium alginate: 0.2 ul/min; the operation period of the pneumatic pump valve is as follows: 0.4 s.

(4) And (3) forming and characterizing the sodium alginate-chitosan composite microcapsule: and (3) the dispersed phase droplet containing the sodium alginate formed in the step (3) reaches the intersection 2(14) through the droplettemplate forming channel 10, and is contacted with the continuous phase containing chitosan, and the sodium alginate molecules with negative charges on the surface of the droplet and the chitosan with positive charges outside the droplet are subjected to cross-linking reaction on the surface of the droplet to form the sodium alginate-chitosan composite microcapsule taking the dispersed phase droplet containing the sodium alginate as the template. The composite microcapsule can be characterized by optical microscope and fluorescence microscope to observe its morphology and size, etc., as shown in fig. 4.

Claims (4)

Translated fromChinese

1.一种基于双水相体系的海藻酸钠-壳聚糖复合微囊制备方法，其特征在于：包括下列步骤：1. a sodium alginate-chitosan composite microcapsule preparation method based on a two-phase system, is characterized in that: comprise the following steps:(1)微流控芯片的制备：利用常规软光刻的方法，制备集成了气动泵阀的聚二甲基硅氧烷(PDMS)芯片；该芯片用于生成液滴模板和制备海藻酸钠-壳聚糖复合微囊，(1) Preparation of microfluidic chip: Using conventional soft lithography, a polydimethylsiloxane (PDMS) chip integrated with a pneumatic pump valve was prepared; the chip was used to generate droplet templates and prepare sodium alginate - Chitosan composite microcapsules,所述芯片包括含壳聚糖的连续相入口(1)，连续相入口(2)，气体入口(3)，含海藻酸钠的分散相入口(4)，微囊出口(5)，含壳聚糖的连续相通道(6)，连续相通道(7)，气体通道(8)，含海藻酸钠的分散相通道(9)，液滴模板形成通道(10)，微囊形成通道(11)，气动微阀(12)，交叉口1(13)和交叉口2(14)组成；The chip comprises a continuous phase inlet (1) containing chitosan, a continuous phase inlet (2), a gas inlet (3), a dispersed phase inlet (4) containing sodium alginate, a microcapsule outlet (5), a shell containing Continuous phase channel for glycans (6), continuous phase channel (7), gas channel (8), disperse phase channel containing sodium alginate (9), droplet template forming channel (10), microcapsule forming channel (11) ), pneumatic micro-valve (12), intersection 1 (13) and intersection 2 (14);含壳聚糖的连续相入口(1)通过含壳聚糖的连续相通道(6)、交叉口2(14)和微囊形成通道(11)与微囊出口(5)相连；连续相入口(2)和含海藻酸钠的分散相入口(4)分别通过连续相通道(7)和含海藻酸钠的分散相通道(9)与交叉口1(13)相连，再通过液滴模板形成通道(10)交叉口2(14)和微囊形成通道(11)与微囊出口(5)相连；气体入口(3)通过气体通道(8)与气动微阀(12)相连；The chitosan-containing continuous phase inlet (1) is connected to the microcapsule outlet (5) through the chitosan-containing continuous phase channel (6), the intersection 2 (14) and the microcapsule forming channel (11); the continuous phase inlet (2) and the sodium alginate-containing dispersed phase inlet (4) are connected to the intersection 1 (13) through the continuous phase channel (7) and the sodium alginate-containing dispersed phase channel (9), respectively, and are formed by droplet templates. The channel (10) intersection 2 (14) and the microcapsule form a channel (11) that is connected to the microcapsule outlet (5); the gas inlet (3) is connected to the pneumatic microvalve (12) through the gas channel (8);(2)双水相溶液的准备：将海藻酸钠溶于葡聚糖水溶液作为含海藻酸钠的分散相，以聚乙二醇(PEG)水溶液为连续相，将壳聚糖溶于PEG水溶液作为含壳聚糖的连续相；(2) Preparation of aqueous two-phase solution: Dissolve sodium alginate in aqueous dextran solution as a disperse phase containing sodium alginate, and use aqueous polyethylene glycol (PEG) solution as continuous phase, dissolve chitosan in aqueous PEG solution as a continuous phase containing chitosan;含海藻酸钠的分散相中可以混合水溶性药物、益生菌或细胞实现相应物质的负载；The disperse phase containing sodium alginate can be mixed with water-soluble drugs, probiotics or cells to achieve the loading of corresponding substances;(3)微流体的操控：含壳聚糖的连续相通过入口(1)进入微流控芯片中，然后沿着含壳聚糖的连续相通道(6)到达交叉口2(14)；连续相，压缩空气和含海藻酸钠的分散相依次通过连续相入口(2)，气体入口(3)和含海藻酸钠的分散相入口(4)进入微流控芯片中，然后依次沿着连续相通道(7)，气体通道(8)和含海藻酸钠的分散相通道(9)到达交叉口1(13)，其中的压缩空气将驱动气动泵阀发生周期性的膨胀，从而挤压含海藻酸钠的分散相通道(9)，促进含海藻酸钠的分散相液滴的形成；(3) Microfluidic manipulation: the continuous phase containing chitosan enters the microfluidic chip through the inlet (1), and then reaches the intersection 2 (14) along the continuous phase channel (6) containing chitosan; continuous Phase, compressed air and the dispersed phase containing sodium alginate enter the microfluidic chip sequentially through the continuous phase inlet (2), the gas inlet (3) and the dispersed phase inlet (4) containing sodium alginate, and then follow the continuous phase in turn. The phase channel (7), the gas channel (8) and the dispersed phase channel (9) containing sodium alginate reach the intersection 1 (13), where the compressed air will drive the pneumatic pump valve to expand periodically, thereby squeezing the The disperse phase channel (9) of sodium alginate promotes the formation of disperse phase droplets containing sodium alginate;(4)海藻酸钠-壳聚糖复合微囊的形成和表征：步骤(3)中形成的含海藻酸钠的分散相液滴将经由液滴模板形成通道(10)到达交叉口2(14)，并在此处与含壳聚糖的连续相接触，液滴表面带有负电荷的海藻酸钠分子与液滴外带有正电荷的壳聚糖在液滴表面发生交联反应，形成以含海藻酸钠的分散相液滴为模板的海藻酸钠-壳聚糖复合微囊。(4) Formation and characterization of sodium alginate-chitosan composite microcapsules: The sodium alginate-containing dispersed phase droplets formed in step (3) will reach the intersection 2 (14) through the droplet template forming channel (10) ), and in contact with the continuous phase containing chitosan, the negatively charged sodium alginate molecules on the droplet surface and the positively charged chitosan outside the droplet undergo a cross-linking reaction on the droplet surface to form Sodium alginate-chitosan composite microcapsules using dispersed phase droplets containing sodium alginate as a template.2.根据权利要求1所述的一种基于双水相体系的海藻酸钠-壳聚糖复合微囊制备方法，其特征在于：泵阀与分散相通道间距40-60μm，泵阀间的分散相通道宽40-60μm，所有通道宽度及高度均为100-400μm。2. a kind of preparation method of sodium alginate-chitosan composite microcapsule based on a two-phase system according to claim 1, is characterized in that: pump valve and disperse phase channel spacing 40-60 μm, dispersion between pump valve The phase channels are 40-60 μm wide, and all channel widths and heights are 100-400 μm.3.根据权利要求1所述的一种基于双水相体系的海藻酸钠-壳聚糖复合微囊制备方法，其特征在于：使用的PEG分子量范围：4000-20000Da、浓度范围：5-50％g/ml；葡聚糖分子量范围：70k-500kDa、浓度范围：5-20％g/ml；海藻酸钠粘度范围：55-850cps、浓度范围：0.5-2％g/ml；壳聚糖粘度范围：100-400cps、浓度范围：0.5-3％g/ml。3. a kind of sodium alginate-chitosan composite microcapsule preparation method based on water two-phase system according to claim 1 is characterized in that: the PEG molecular weight range of use: 4000-20000Da, concentration range: 5-50 %g/ml; Dextran Molecular Weight Range: 70k-500kDa, Concentration Range: 5-20% g/ml; Sodium Alginate Viscosity Range: 55-850cps, Concentration Range: 0.5-2% g/ml; Chitosan Viscosity range: 100-400cps, concentration range: 0.5-3% g/ml.4.根据权利要求1所述的一种基于双水相体系的海藻酸钠-壳聚糖复合微囊制备方法，其特征在于：含壳聚糖的连续相流速范围：2-6ul/min；连续相流速范围：1-4ul/min；气体气压范围：10-60kPa；含海藻酸钠的分散相流速范围：0.1-0.4ul/min；气动泵阀运行周期范围：0.1-0.8s。4. a kind of sodium alginate-chitosan composite microcapsule preparation method based on two-water-phase system according to claim 1, is characterized in that: the continuous phase flow rate scope containing chitosan: 2-6ul/min; Continuous phase flow rate range: 1-4ul/min; gas pressure range: 10-60kPa; disperse phase flow rate range containing sodium alginate: 0.1-0.4ul/min; pneumatic pump valve operating cycle range: 0.1-0.8s.

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